Container for the storage and delivery of a fluid or pasty material

ABSTRACT

A tube or like hollow cylindrical container for the storage and delivery of a fluid or pasty material has an insert fitted into one end. The insert comprises a piston axially movable along the tube, a bottom for the container, a bellows-type bag containing gas under pressure and acting between the container bottom and the back of the piston and spring hooks on the piston engageable with holes in the container bottom so that the piston is prevented from moving away from the container bottom, the hooks being releasable from the outside when material is to be delivered from the container. Various modifications of this constructions are described and illustrated.

tates 1 tet Inventor Otto Berkmuller 14a Willibaldstrasse, 8 Miinich 21,Germany Appl. No. 869,670 Filed Oct. 27, 1969 Patented Oct. 19, 1971Priority Oct. 31, 1968 Germany CONTAINER FOR THE STORAGE AND DELXVERY OFA FLUID OR PASTY MATERIAL Primary Examiner-Samuel F. ColemanAtt0mey-0berlin, Maky, Donnelly & Renner ABSTRACT: A tube or like hollowcylindrical container for the storage and delivery of a fluid or pastymaterial has an inscrt fitted into one end. The insert comprises apiston axially movable along the tube, a bottom for the container, abellowstype bag containing gas under pressure and acting between thecontainer bottom and the back of the piston and spring books on thepiston engageable with holes in the container bottom so that the pistonis prevented from moving away from the container bottom, the hooks beingreleasable from the outside when material is to be delivered from thecontainer. Various modifications of this constructions are described andillustrated.

PATENTEDBBT 19:97: 3,613,963 SHEET 30F 4 INVI'IN'I'URI 0TH] BERKMULLERPAIENTEBum 19 I97! 3.613.963

sum 0F 4 0TH] BERKMULLER CONTAINER FOR THE STORAGE AND DELIVERY OF AFLUID R PASTY MATERKAL The invention relates to a tube or like hollowcylindrical container for the storage and delivery of a fluid or pastymaterial, having a piston which is longitudinally movable in thecontainer to urge the material to the delivery aperture and which can beurged forwardly by a pressure medium contained in an insert fitted intothe container.

A container of this type is shown in FIG. 1 of French Pat. SpecificationNo. 1,046,624 in which the insert containing the drive gas or otherpressure medium comprises a rigid-walled chamber at the bottom of thecontainer and which is provided with a gas valve which opens to allowthe generation below the driving piston of a gas pressure which tends tourge the piston towards the delivery aperture of the container. Thiscontainer suffers on the one hand from the disadvantage that, althoughthe gas valve is closed after use, there remains a gas pressure actingdirectly against the piston, whereby gases can pass between thecontainer wall and the piston into the contents of the container and mixtherewith so that such a container is not suited for the storage offoodstuffs such as whipped cream, cheese and the like. On the otherhand, a container of this nature is an expensive construction as the gasvalve represents a considerable part of the costs and also requiresparticular seal- The invention is based on the problem of designing acontainer of the type shown in the French specification in such a waythat the disadvantages from which it suffers hitherto are eliminated,and in particular the contents and the drive gas are completelyseparated without the bottom of the container requiring a gastight seal.

In accordance with the invention, the driving piston is loadable on itsside remote from the delivery aperture, by a preferably bellowslikefoldable bag which is enclosed in the container and contains thepressure medium and which, together with the container bottom, forms theinsert fitted into the container.

While, therefore, in the case of a container with a gas valve, pressureis only generated when required by opening the gas valve, and is thendisadvantageously maintained, in the container according to theinvention there is already a pressure before the container used, thispressure being stored in the expandable bag.

Storing the pressure gas in the bag insert means that there is nopossibility of pressure gas and container contents being mixed. ln FIG.3 of French Pat. Specification No. 1,046,624, gas is made to flow fromthe rigid-walled chamber by way of the gas valve into a bag insertwhich, by expansion, then urges the container contents towards thedelivery aperture directly, that is without the interposition of apiston. With this construction, however, it is not possible for thecontainer to be completely emptied. In this case, too, a separate gasvalve is required which increases the production costs of the container.Therefore, the container according to the invention can be produced moresimply and cheaply particularly as, in addition to the omission of a gasvalve, combining the parts forming the insert into a unit which can beprepared separately enables the container to be produced at an even morefavorable cost, as these parts can be produced in a single workpiece,for example of plastics material.

In accordance with a preferred embodiment of the container according tothe invention, the bag which contains the pressure medium can be securedto a part of the container, at least when the container is full, by anexternally releasable lock means which is part of the insert and allowsthe pressure medium for advancing the piston to take effect only afterit has been released. In the containers shown in the Frenchspecification, the manually operable gas valve allows the pressuremedium to take effect to drive out the filling material only after thevalve has been opened, but in this embodiment of the invention theexpandable bag which contains the gas stored in a liquefied form is atfirst secured b the mechanical look means so that the pressure cannotact on the material before the container is used. The locking action onthe pressure medium bag is only removed when the tubular container is tobe used for the first time to deliver its contents, so that at leastuntil that moment, the contents and, therefore, the container itself arenot under the pressure of the drive gas. Only when the locking actionhas been released does the pressure of the gas in the bag insert act onthe driving piston which transmits this pressure to the containercontents and permits them to issue as required from the containerthrough the delivery aperture.

Combining the bag insert and the container bottom with the lock means toform a unit which is separate from the container before filling, alsoprovides however further advantages. On the one hand, this insertincluding the gas filling can be manufactured in a preproductionprocess. In this case, this insert is produced separately from theoperation of filling the container with the particular material inquestion. This insert is also desirably supplied to the tubemanufacturer separately from the containers; as in this case, owing tothe locking action on the bag, the gas is stored in an extremely smallspace, such inserts are extraordinarily compact for delivery purposes,and require little packaging material. The manufacture of this separateinsert also enjoys the advantage that it permits particularly rationalfilling and closing of the container as the entire open bottom surfacearea of the container is available for filling and the container can besealed in a rational manner after the filling operation simply byapplying a pressure, for example engaging the container bottom whichforms one part of this insert, in a bead formed in the wall of thecontainer at its free end. Obviously, however, it is also possible forthe container to be supplied to the factory with the insert alreadyfitted and including the gas charge, the factory when filling thecontainer in this case by way of the delivery aperture of the container.At any event, the tubular container does not need to be airtight sealedas the drive gas is contained in the bag insert in an airtight manner.As the pressure force of the gas contained in the bag insert is in mostcases only released by the consumer releasing the lock means, when thecontainer to be used for the first time, it is practically impossiblefor the container to be unintentionally discharged during transportationand storage.

In accordance with a particularly advantageous form of this preferredembodiment of the container according to the invention, to provide themechanical lock means for the bag, the driving piston forming the headthereof has extensions with, for example, hook-shaped ends which can beengaged into holes in the container bottom or in recesses provided inthe lower wall region of the container. Therefore, in this embodiment,the driving piston is incorporated in the insert formed by the bag,container bottom and lock means, resulting generally in even greatsimplification of manufacture of the container. In addition, such acontainer offers considerable safety as regards the danger of accidentthe case of damage caused by excess pressure, as such excess pressurecan escape through the holes provided for the lock means in thecontainer bottom, or the recesses in the wall of the container, thusfalling to such an extent that the container can be made with arelatively small wall thickness without thereby substantiallyendangering its operating reliability.

The same advantage is found when, in accordance with a furtherembodiment of the invention, for providing the mechanical lock means forthe bag, the head of the bag or a plate carried thereby has extensionswith, for example, spherical ends which can engage in wedge-shaped slotsformed in the container bottom, while the piston which is producedseparately from the bag, preferably comprises resilient material.

in both embodiments, the locking action on the bag insert is releasedinsofar as the hook-shaped or spherical ends of the extensions of thedriving piston or the bag or its head plate are disengaged so that forthe first and all further discharging operations, the drive gas acts byway of thedriving piston on the contents of the container. Obviously,the extensions provided for the lock means may also be made of such alength that even when the container has been partly discharged, they canstill be gripped from the outside and reengaged so that in this way thecontents still stored in the container can be relieved of pressure aftereach time that the container has been used, and so that the bag insertmay possibly be retracted by means of the extended portions to itsstarting position when the container has been completely emptied, sothat the container with insert can again be used for discharging furthermaterial introduced into the container.

It is further advantageous for the peripheral edges of the piston to beprovided with sealing lips or to be formed as sealing lips. In this way,there is always a sufficient seal between the space in which thecontents of the container are contained, and the space in the containerwhich is separated from the contents by the piston and which is occupiedby the bag insert loaded by the gas pressure, even when the container isnot completely cylindrical and the piston does not move completelycoaxially in the container.

The driving piston desirably has a cylindrical cavity to accommodate thebag together with the container bottom, before the container is put touse. Thus, when the container is completely full, the bag insertdisappears in the folded condition into this cavity in the piston andtherefore requires the minimum amount of space. This cavity is desirablyof such a size that the lower edge of the piston lies substantiallyagainst the container bottom so that the gas pressure in the bag insertonly acts on the peripheral wall of the hollow piston but not on thewall of the container, so that its cross section can be made extremelysmall. In this case, it is possible for the bag containing the pressuremedium to be of a smaller cross section than the cavity in the drivingpiston so that the pressure force acting on the material to bedischarged can be favorably selected to correspond to the nature of suchmaterial.

The gas used to fill the container insert can be impure, and thereforecheap, gases as the above proposed construction prevents any mixing ofthe gas and the filling material. Instead of hook-shaped or sphericalends for locking the extensions forming the mechanical lock means forthe bag insert, snaplocking or bayonetlike means can also be used, orfor example tearoff foils can be provided, by means of which the lockmeans can be particularly easily released. Assembly of the containeraccording to the invention, which is preferably only in two parts, canbe effected particularly simply when the bag insert is arranged to beengaged into the container without requiring any screw or weldedconnection. The driving gas charge can also be introduced into the baginsert after it has been fitted into the container, this being effectedfor example at the same time as the contents are introduced into thecontainer by way ofits delivery aperture.

A number of embodiments given by way of example of a tubular containerin accordance with the invention are shown in diagrammatic form in theaccompanying drawing, in which:

FIG. 1 shows a cross-sectional exploded view of the insert to be fittedinto the container, comprising a driving piston, a bag containingpressure gas, a container bottom and lock means,

FIG. 2 shows the same insert in the compressed and locked butready-for-use condition,

FIG. 3 shows a container according to the invention with fitted andcompressed insert, with the lock means holding the bag,

FIG. 3a shows the same container as FIG. 3 but after it has been put touse, that is with the bag in the released condition after the storedmaterial has already been partly discharged,

FIG. 4 shows another embodiment of the upper part of the insert,

FIG. 5 shows the lower part of the container with another form of thebag lock means, and

FIG. 6 shows a further embodiment of the upper region of the insert.

As shown in FIG. 1, the insert 1 comprises a driving piston 2, into acavity 3 in which is fitted a bellows-shaped bag 4 containing drive gas,the drive gas being fed to the bag 4 by way of a gas filling connection5 in a container bottom 6. The container bottom 6 has holes 7 foraccommodating hook-shaped extensions 8 on the piston 2, for the purposeof initial locking.

FIG. 2 shows that, with the bag 4 still compressed and the piston 2 inthe locked condition at the container bottom 6, the insert 1 contains,the remaining space, gas 10 which is in liquefied form and which isprevented from premature vaporization by the locking action of theextensions 8. The liquid drive gas 10 is introduced by way of the gasfilling connection 5 which is then sealed with a closure member 11.

As shown in FIG. 3, the above described insert is fitted at the base ofa container 14 which contains material 15. When the extended portions 8are released, the bag 4 of the insert 1 unfolds and, owing to the gaspressure therein, urges the material 15 towards the delivery aperture ofthe container 14 by way of the piston 2. To seal the piston 2 whichmoves upwardly to displace the material 15, the piston 2 carries astrong wedge-shaped outwardly extending peripheral sealing lip 20 withone or more sealing flanges 21 below it, while below the sealing flanges21 is a guide shoulder 22 of substantially smaller diameter. Thefunction of these sealing members is clearly apparent from FIG. 3.

In the embodiment shown in FIG. 4, the extensions for mechanicallylocking the bag 4 are provided on a plate 18 arranged on the head 16 ofthe bag 4 and terminate in spherical ends 13 which engage inwedge-shaped slots provided in the container bottom when the bag 4 isstill compressed. The piston 12 which is separate from the bag 4preferably comprises resilient material.

In the embodiment shown in FIG. 5, with the bag 4 in the foldedcondition the extensions 8 provided for locking purposes engage withtheir downwardly extending hooks into recesses 17 provided on both sidesin the wall of the container 14 in the lower region thereof.

As shown in FIG. 6, the drive gas bag 25 is made with a smaller outsidediameter than the cavity 3 in the piston 2 into which the gas bag 25 isinserted with its upper end cup 26.

In all the embodiments shown, the delivery aperture in the container andthe closure member which is in any case required and which is openedeach time that material is to be discharged from the container, are notshown as these parts are not the subject of the present invention andmay be of conventional form (cf. the French specification mentionedabove).

I claim:

1. A hollow cylindrical container for storing and delivering fluidmaterial, said container comprising a hollow cylindrical casing, apiston axially slidable in said casing to urge said material towards oneend of said casing for delivery, a casing end member for the other endof said casing, a foldable bag containing pressurized gas extendingaxially in said casing between said piston and said casing end memberfor urging said piston towards said one end of said casing, andexternally releasable mechanical lock means extending longitudinally ofsaid casing outside said bag and preventing axial expansion of said baguntil said lock means is released, at least said casing end member, saidfoldable bag and said lock means forming an insert adapted to be fittedinto said casing.

2. A container according to claim 1, wherein said piston is part of saidinsert.

3. A container according to claim 2, wherein said lock means comprisesat least one axially extending extension on said piston engageable atthe free end thereof in at least one hole or recess in said casing.

4. A container according to claim 2, wherein said lock means comprisesat least one axially extending extension on said piston engageable atthe free end thereof in at least one hole or recess in said casing endmember.

5. A container according to claim 1, wherein said bag has a headplateadjacent said piston and said lock means comprises at least one axiallyextending extension on said headplate.

6. A container according to claim I, wherein said piston has sealinglips thereon.

8. A container according to claim 7, wherein said bag has asubstantially smaller cross section than said cavity.

1. A hollow cylindrical container for storing and delivering fluidmaterial, said container comprising a hollow cylindrical casing, apiston axially slidable in said casing to urge said material towards oneend of said casing for delivery, a casing end member for the other endof said casing, a foldable bag containing pressurized gas extendingaxially in said casing between said piston and said casing end memberfor urging said piston towards said one end of said casing, andexternally releasable mechanical lock means extending longitudinally ofsaid casing outside said bag and preventing axial expansion of said baguntil said lock means is released, at least said casing end member, saidfoldable bag and said lock means forming an insert adapted to be fittedinto said casing.
 2. A container according to claim 1, wherein saidpiston is part of said insert.
 3. A container according to claim 2,wherein said lock means comprises at least one axially extendingextension on said piston engageable at the free end thereof in at leastone hole or recess in said casing.
 4. A container according to claim 2,wherein said lock means comprises at least one axially extendingextension on said piston engageable at the free end thereof in at leastone hole or recess in said casing end member.
 5. A container accordingto claim 1, wherein said bag has a headplate adjacent said piston andsaid lock means comprises at least one axially extending extension onsaid headplate.
 6. A container according to claim 1, wherein said pistonhas sealing lips thereon.
 7. A container according to claim 1, whereinsaid piston has a cylindrical cavity to accommodate said bag and saidcasing end member before the container is used.
 8. A container accordingto claim 7, wherein said bag has a substantially smaller cross sectionthan said cavity.